Organometallic compound and organic light-emitting device including the same

ABSTRACT

An organometallic compound represented by Formulae 1, 2, or 3 below: 
     
       
         
         
             
             
         
       
     
     wherein in Formulae 1, 2, and 3, groups and variables are the same as in the specification.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Korean Patent Application No.10-2014-0053101, filed on May 1, 2014, in the Korean IntellectualProperty Office, and all the benefits accruing thereof under 35 U.S.C.§119, the disclosure of which is incorporated herein in its entirety byreference.

BACKGROUND

1. Field

One or more embodiments relate to an organometallic compound and anorganic light-emitting device including the same.

2. Description of the Related Art

Organic light emitting devices are self-emission devices that have wideviewing angles, high contrast ratios, and short response times. Inaddition, OLEDs have excellent brightness, driving voltage, and responsespeed characteristics, and produce full-color images.

A typical organic light-emitting device includes an anode, a cathode,and an organic layer that is disposed between the anode and the cathodeand includes an emission layer. A hole transport region may be disposedbetween the anode and the emission layer, and an electron transportregion may be disposed between the emission layer and the cathode. Holesprovided from the anode may move toward the emission layer through thehole transport region, and electrons provided from the cathode may movetoward the emission layer through the electron transport region.Carriers, such as holes and electrons, are recombined in the emissionlayer to produce excitons. These excitons change from an excited stateto a ground state, thereby generating light.

Different types of organic light emitting devices are known. However,there still remains a need in OLEDs having low driving voltage, highefficiency, high brightness, and long lifespan.

SUMMARY

Provided are a novel organometallic compound and an organiclight-emitting device including the same.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an aspect, an organometallic compound is represented byFormula 1, 2, or 3 below:

wherein in Formulae 1, 2, and 3,

M may be Al, Ga, Be, Mg, or Zn;

CY₁, CY₂, CY₁₁, and CY₂₁ may be each independently a nitrogen-containingheterocyclic group;

CY₁₂ is selected from an aromatic cyclic group and a non-aromatic cyclicgroup;

X₁ may be N or C,

X₁₁ may be N or C,

X₁₂ may be N or C,

X₂₁ may be N or CR₂₁,

X₂₂ may be N or CR₂₂,

X₂₃ may be N or CR₂₃, and

X₂₄ may be S, O, Si(R₂₄)(R₂₅), or N(R₂₆);

Z₁, Z₂, Z₁₁, Z₁₂, Z₂₁, and R₂₁ to R₂₆ may be each independently selectedfrom a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₂-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), and —B(Q₆)(Q₇);

Z₃ and Z₁₃ may each be an electron withdrawing group;

a1, a2, a3, a11, a12 and a21 may be each independently an integerselected from 0 to 5;

a13 is an integer selected from 1 to 5;

n1 is an integer selected from 1 to 3;

L₁ is selected from a monovalent organic ligand, a divalent organicligand, and a trivalent organic ligand;

n2 is an integer selected from 0 to 3;

provided that

CY₂ in Formula 1 may not be a triazine, a pyridazine, and a pyrimidine;

substituents of two adjacent ligands in Formulae 1 and 2 may not belinked to each other;

in Formula 3, when X₂₄ is N(R₂₆), at least one selected from X₂₁ to X₂₃may be N;

at least one substituent of the substituted C₁-C₆₀ alkyl group, thesubstituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group,the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₂-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₂-C₆₀heteroaryl group, the substituted a monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group may be selected from

a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid ora salt thereof, a phosphoric acid or a salt thereof, a C₃-C₁₀ cycloalkylgroup, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), and—B(Q₁₆)(Q₁₇);

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), and—B(Q₂₆)(Q₂₇); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), and —B(Q₃₆)(Q₃₇);

wherein Q₁ to Q₇, Q₁₁ to Q₁₇, Q₂₁ to Q₂₇, and Q₃₁ to Q₃₇ may be eachindependently a hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group,a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkylgroup, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,or a monovalent non-aromatic condensed heteropolycyclic group.

According to another aspect, an organic light-emitting device includes:

a first electrode;

a second electrode; and

an organic layer disposed between the first electrode and the secondelectrode,

wherein the organic layer includes an emission layer, and includes atleast one of the organometallic compound represented by Formula 1.

The organometallic compound may be included in the emission layer, theorganometallic compound included in the emission layer may act as ahost, and the emission layer may further include a phosphorescentdopant.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with FIG. 1 which is a schematic view of an organiclight-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the present description. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

It will be understood that when an element is referred to as being “on”another element, it can be directly in contact with the other element orintervening elements may be present therebetween. In contrast, when anelement is referred to as being “directly on” another element, there areno intervening elements present.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer, orsection from another element, component, region, layer, or section.Thus, a first element, component, region, layer, or section discussedbelow could be termed a second element, component, region, layer, orsection without departing from the teachings of the present embodiments.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

The term “or” means “and/or.” It will be further understood that theterms “comprises” and/or “comprising,” or “includes” and/or “including”when used in this specification, specify the presence of statedfeatures, regions, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, regions, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this general inventive conceptbelongs. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand the present disclosure, and will not be interpreted in an idealizedor overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

An organometallic compound according to an embodiment is represented byFormula 1, 2, or 3 below:

M in Formulae 1 to 3 may be aluminum (Al), gallium (Ga), beryllium (Be),magnesium (Mg), or zinc (Zn).

For example, M in Formulae 1 to 3 may be aluminum or zinc, but is notlimited thereto.

In Formulae 1 to 3, CY₁, CY₂, CY₁₁, and CY₂₁ may be each independently anitrogen-containing heterocyclic group, and CY₁₂ may be selected from anaromatic cyclic group and a non-aromatic cyclic group.

CY₂ may be a nitrogen-containing heterocyclic group having one nitrogen(N) as a ring forming element.

According to an embodiment, CY₁, CY₁₁, and CY₂₁ in Formulae 1 to 3 maybe each independently selected from a pyridine, a pyrazine, apyrimidine, a pyridazine, a triazine, a quinoline, an isoquinoline, abenzoquinoline, a quinoxaline, a quinazoline, a triazole, an oxazole, abenzooxazole, and a benzoisoquinoline, and CY₂ may be selected from apyridine, a quinoline, and an isoquinoline, but they are not limitedthereto.

According to an embodiment, CY₁₂ in Formula 2 may be selected from abenzene, a naphthalene, a fluorene, a phenanthrene, an anthracene, afluoranthene, a triphenylene, a pyrene, and a chrysene, but is notlimited thereto.

In Formulae 1 to 3,

X₁ may be N or C,

X₁₁ may be N or C,

X₁₂ may be N or C,

X₂₁ may be N or CR₂₁,

X₂₂ may be N or CR₂₂,

X₂₃ may be N or CR₂₃, and

X₂₄ may be S, O, Si(R₂₄)(R₂₅), or N(R₂₆);

Z₁, Z₂, Z₁₁, Z₁₂, Z₂₁, and R₂₁ to R₂₆ may be each independently selectedfrom a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₂-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), and —B(Q₆)(Q₇).

For example, Z₁, Z₂, Z₁₁, Z₁₂, Z₂₁, R₂₁ to R₂₆ may be each independentlyselected from

a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid or a salt thereof, asulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, aC₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, and a phosphoric acid or a saltthereof;

a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group,an azulenyl group, a heptalenyl group, an indacenyl group, anacenaphthyl group, a fluorenyl group, a spiro-fluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, aphenanthrenyl group, an anthracenyl group, a fluoranthenyl group, atriphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenylgroup, a picenyl group, a perylenyl group, a pentaphenyl group, ahexacenyl group, a pentacenyl group, a rubicenyl group, a coronenylgroup, an ovalenyl group, a pyrrolyl group, a thiophenyl group, afuranyl group, an imidazolyl group, a pyrazolyl group, a thiazolylgroup, an isothiazolyl group, an oxazolyl group, an isooxazolyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, an isoindolyl group, an indolyl group, an indazolyl group, afurinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzooxazolyl group, an isobenzooxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a thiadiazolyl group, animidazopyridinyl group, and an imidazopyrimidinyl group;

a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group,an azulenyl group, a heptalenyl group, an indacenyl group, anacenaphthyl group, a fluorenyl group, a spiro-fluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, aphenanthrenyl group, an anthracenyl group, a fluoranthenyl group, atriphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenylgroup, a picenyl group, a perylenyl group, a pentaphenyl group, ahexacenyl group, a pentacenyl group, a rubicenyl group, a coronenylgroup, an ovalenyl group, a pyrrolyl group, a thiophenyl group, afuranyl group, an imidazolyl group, a pyrazolyl group, a thiazolylgroup, an isothiazolyl group, an oxazolyl group, an isooxazolyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, an isoindolyl group, an indolyl group, an indazolyl group, afurinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl, an acridinyl, a phenanthrolinyl, aphenazinyl, a benzoimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzooxazolylgroup, an isobenzooxazolyl group, a triazolyl group, a tetrazolyl group,an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, an imidazopyridinyl group, and an imidazopyrimidinyl group, eachsubstituted with at least one selected from a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a pentalenyl group, an indenyl group, a naphthyl group, anazulenyl group, a heptalenyl group, an indacenyl group, an acenaphthylgroup, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenylgroup, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenylgroup, an anthracenyl group, a fluoranthenyl group, a triphenylenylgroup, a pyrenyl group, a chrysenyl group, a naphthacenyl group, apicenyl group, a perylenyl group, a pentaphenyl group, a hexacenylgroup, a pentacenyl group, a rubicenyl group, a coronenyl group, anovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group,an imidazolyl group, a pyrazolyl group, a thiazolyl group, anisothiazolyl group, an oxazolyl group, an isooxazolyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, anisoindolyl group, an indolyl group, an indazolyl group, a furinyl group,a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl, an acridinyl, a phenanthrolinyl, a phenazinyl, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzooxazolyl group, an isobenzooxazolylgroup, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, atriazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, and a biphenyl group; and

—N(Q₁)(Q₂) and —Si(Q₃)(Q₄)(Q₅);

wherein Q₁ to Q₅ may be each independently selected from a hydrogen, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthylgroup, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, afluorenyl group, a chrysenyl group, a carbazolyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a pyridinyl group, a pyrimidinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinazolinyl group, and a quinoxalinyl group, but they are not limitedthereto.

In some embodiments, Z₁, Z₂, Z₁₁, Z₁₂, Z₂₁, and R₂₁ to R₂₆ may be eachindependently

a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid or a salt thereof, asulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, aC₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, and a phosphoric acid or a saltthereof;

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrimidinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, and a carbazolyl group; and

a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrimidinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, and a carbazolyl group, each substituted with atleast one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthylgroup, a fluorenyl group, a spiro-fluorenyl group, a phenalenyl group, aphenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenylgroup, a pyridinyl group, a pyrimidinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, and acarbazolyl group, but they are not limited thereto.

Z₃ and Z₁₃ in Formulae 1 and 2 may each be an EWG.

According to an embodiment, Z₃ and Z₁₃ may be each independently an EWGselected from

—F, a cyano group, a nitro group, a pyridinyl group, and a pyrimidinylgroup; and

a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthylgroup, a pyridinyl group, and a pyrimidinyl group, each substituted withat least one selected from —F, a cyano group, a nitro group, a pyridinylgroup, and a pyrimidinyl group.

In some embodiments, Z₃ and Z₁₃ may be each independently an EWGselected from —F, a cyano group, a nitro group, a pyridinyl group, apyrimidinyl group, —CF₃, and —CF₂CF₃.

a1, a2, a3, a11, a12, and a21 in Formulae 1 to 3 may be eachindependently an integer selected from 0 to 5. For example, a1, a2, a3,a11, a12, and a21 may be each independently 0, 1, or 2.

a1 indicates the number of Z₁, and when a1 is 2 or more, groups Z₁ maybe identical or different. a2, a3, a11, a12, and a21 may be understoodin the same manner as described in connection with a1 by referring toFormulae 1 to 3.

According to an embodiment, a3 in Formula 1 may be an integer selectedfrom 1 to 5. For example, a3 in Formula 1 may be 1 or 2. When a3 is not0, CY₂ in Formula 1 has an EWG as a substituent.

a13 in Formula 2 may be an integer selected from 1 to 5. For example,a13 may be 1 or 2. Since a13 is not 0, CY₁₂ in Formula 2 has at leastone EWG as a substituent.

In some embodiments, at least one group Z₁ in Formula 1 may be an EWG,and at least one group Z₁₁ in Formula 2 may be an EWG. A specificexample of the EWG may be understood by referring to the descriptionpresented in connection with Z₃.

n1 in Formulae 1 to 3 may be an integer selected from 1 to 3. Forexample, n1 in Formulae 1 to 3 may be 2 or 3, but is not limitedthereto.

L₁ in Formulae 1 to 3 is selected from a monovalent organic ligand, adivalent organic ligand, and a trivalent organic ligand. The monovalentorganic ligand, the divalent organic ligand, and the trivalent organicligand may be selected from known organic ligands.

For example, L₁ may be selected from a halogen ligand (for example, Clor F), a diketone ligand (for example, acetylacetonate,1,3-diphenyl-1,3-propandionate, 2,2,6,6-tetramethyl-3,5-heptanedionate,or hexafluoroacetonate), a carboxylic acid ligand (for example,picolinate, dimethyl-3-pyrazole carboxylate, or benzoate), a carbonmonooxide ligand, an isonitrile ligand, a cyano ligand, and aphosphorous ligand (for example, phosphine, and phosphite), but is notlimited thereto.

n2 in Formulae 1 to 3 may be an integer selected from 0 to 3. Forexample, n2 in Formulae 1 to 3 may be 0 or 1. For example, n2 inFormulae 1 to 3 may be 0.

CY₂ in Formula 1 may not be a triazine, a pyridazine, and a pyrimidine.

Substituents of two neighboring ligands in Formulae 1 and 2 may not belinked to each other.

In Formula 3, when X₂₄ is N(R₂₆), at least one selected from X₂₁ to X₂₃may be N.

According to an embodiment, the organometallic compound represented byFormula 1 may be represented by one of Formulae 1A to 1K below:

M, Z₁ to Z₃, a1 to a3, n1, L₁, n2, and CY₂ in Formulae 1A to 1K havealready been described in detail above.

For example, in Formulae 1A to 1K,

CY₂ may be a pyridine, a quinoline, or an isoquinoline;

Z₁ to Z₃ may be each independently selected from

a hydrogen, —F, a cyano group, a nitro group, a methyl group, an ethylgroup, a propyl group, an n-butyl group, an isobutyl group, a sec-butylgroup, a tert-butyl group, an n-pentyl group, an isopentyl group, asec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexylgroup, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, anisoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octylgroup, an isooctyl group, a sec-octyl group, a tert-octyl group, ann-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group,an n-decanyl group, an isodecanyl group, a sec-decanyl group, atert-decanyl group, a methoxy group, an ethoxy group, a propoxy group, abutoxy group, a pentoxy group, a phenyl group, a naphthyl group, apyridinyl group, and a pyrimidinyl group; and

a methyl group, an ethyl group, a propyl group, an n-butyl group, anisobutyl group, a sec-butyl group, a tert-butyl group, an n-pentylgroup, an isopentyl group, a sec-pentyl group, a tert-pentyl group, ann-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group,an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptylgroup, an n-octyl group, an isooctyl group, a sec-octyl group, atert-octyl group, an n-nonyl group, an isononyl group, a sec-nonylgroup, a tert-nonyl group, an n-decanyl group, an isodecanyl group, asec-decanyl group, a tert-decanyl group, a methoxy group, an ethoxygroup, a propoxy, a butoxy group, a pentoxy group, a phenyl group, anaphthyl group, a pyridinyl group, and a pyrimidinyl group, eachsubstituted with at least one selected from —F, a cyano group, a nitrogroup, a C₁-C₂₀ alkoxy group, a C₁-C₂₀ alkoxy group, a phenyl group, anaphthyl group, a pyridinyl group, and a pyrimidinyl group; and a1 to a3may be each independently 0, 1 or 2, but are not limited thereto.

In some embodiments, the organometallic compound may be represented byFormulae 2A, 2B, or 2C:

wherein in Formulae 2A to 2C,

-   M, Z₁₂, Z₁₃, a12, n1, L₁, and n2 have already been described above;-   Z_(13a) and Z_(13b) may be understood by referring to the    description presented in connection with Z₁₃;-   X₁₃ is N or CR₁₃, X₁₄ is N or CR₁₄, X₁₅ is N or CR₁₅, and X₁₆ is N    or CR₁₆;-   R₁₃ to R₁₆ may be understood by referring to the description    provided herein in connection with Z₁₁.

For example, in Formulae 2A to 2C,

-   Z₁₂ and R₁₃ to R₁₆ are each independently selected from

a hydrogen, —F, a cyano group, a nitro group, a methyl group, an ethylgroup, a propyl group, an n-butyl group, an isobutyl group, a sec-butylgroup, a tert-butyl group, an n-pentyl group, an isopentyl group, asec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexylgroup, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, anisoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octylgroup, an isooctyl group, a sec-octyl group, a tert-octyl group, ann-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group,an n-decanyl group, an isodecanyl group, a sec-decanyl group, atert-decanyl group, a methoxy group, an ethoxy group, a propoxy group, abutoxy group, a pentoxy group, a phenyl group, a naphthyl group, apyridinyl group, and a pyrimidinyl group; and

a methyl group, an ethyl group, a propyl group, an n-butyl group, anisobutyl group, a sec-butyl group, a tert-butyl group, an n-pentylgroup, an isopentyl group, a sec-pentyl group, a tert-pentyl group, ann-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group,an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptylgroup, an n-octyl group, an isooctyl group, a sec-octyl group, atert-octyl group, an n-nonyl group, an isononyl group, a sec-nonylgroup, a tert-nonyl group, an n-decanyl group, an isodecanyl group, asec-decanyl group, a tert-decanyl group, a methoxy group, an ethoxygroup, a propoxy, a butoxy group, a pentoxy group, a phenyl group, anaphthyl group, a pyridinyl group, and a pyrimidinyl group, eachsubstituted with at least one selected from —F, a cyano group, a nitrogroup, a C₁-C₂₀ alkoxy group, a C₁-C₂₀ alkoxy group, a phenyl group, anaphthyl group, a pyridinyl group, and a pyrimidinyl group; and

Z₁₃, Z_(13a), and Z_(13b) may be each independently selected from

—F, a cyano group, a nitro group, a pyridinyl group, and a pyrimidinylgroup; and

a methyl group, an ethyl group, a propyl group, an n-butyl group, anisobutyl group, a sec-butyl group, a tert-butyl group, an n-pentylgroup, an isopentyl group, a sec-pentyl group, a tert-pentyl group, ann-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group,an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptylgroup, an n-octyl group, an isooctyl group, a sec-octyl group, atert-octyl group, an n-nonyl group, an isononyl group, a sec-nonylgroup, a tert-nonyl group, an n-decanyl group, an isodecanyl group, asec-decanyl group, a tert-decanyl group, a methoxy group, an ethoxygroup, a propoxy group, a butoxy group, a pentoxy group, a phenyl group,a naphthyl group, a pyridinyl group, and a pyrimidinyl group, eachsubstituted with at least one selected from —F, a cyano group, a nitrogroup, a pyridinyl group, and a pyrimidinyl group, but they are notlimited thereto.

For example, Z₁₃, Z_(13a), and Z_(13b) in Formulae 2A to 2C may be eachindependently selected from —F, a cyano group, a nitro group, apyridinyl group, a pyrimidinyl group, —CF₃, and —CF₂CF₃.

For example, n2 in Formulae 2A to 2C may be 0.

In some embodiments, the organometallic compound may be represented byone of Formulae 3A to 3D:

M, Z₂₁, a21, X₂₁ to X₂₃, R₂₄ to R₂₆, n1, L₁, and n2 in Formulae 3A to 3Dhave already been described above, and at least one of X₂₁ to X₂₃ inFormula 3D may be N.

For example, Z₂₁, and R₂₁ to R₂₆ in Formulae 3A to 3D may be eachindependently selected from

a hydrogen, —F, a cyano group, a nitro group, a methyl group, an ethylgroup, a propyl group, an n-butyl group, an isobutyl group, a sec-butylgroup, a tert-butyl group, an n-pentyl group, an isopentyl group, asec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexylgroup, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, anisoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octylgroup, an isooctyl group, a sec-octyl group, a tert-octyl group, ann-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group,an n-decanyl group, an isodecanyl group, a sec-decanyl group, atert-decanyl group, a methoxy group, an ethoxy group, a propoxy group, abutoxy group, a pentoxy group, a phenyl group, a naphthyl group, apyridinyl group, and a pyrimidinyl group; and

a methyl group, an ethyl group, a propyl group, an n-butyl group, anisobutyl group, a sec-butyl group, a tert-butyl group, an n-pentylgroup, an isopentyl group, a sec-pentyl group, a tert-pentyl group, ann-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group,an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptylgroup, an n-octyl group, an isooctyl group, a sec-octyl group, atert-octyl group, an n-nonyl group, an isononyl group, a sec-nonylgroup, a tert-nonyl group, an n-decanyl group, an isodecanyl group, asec-decanyl group, a tert-decanyl group, a methoxy group, an ethoxygroup, a propoxy, a butoxy group, a pentoxy group, a phenyl group, anaphthyl group, a pyridinyl group, and a pyrimidinyl group, eachsubstituted with at least one selected from —F, a cyano group, a nitrogroup, a C₁-C₂₀ alkoxy group, a C₁-C₂₀ alkoxy group, a phenyl group, anaphthyl group, a pyridinyl group, and a pyrimidinyl group, but they arenot limited thereto.

The organometallic compound may be one of Compounds 1 to 168 below:

CY₂ in Formula 1 may be a nitrogen-containing heterocyclic group, forexample, a nitrogen-containing heterocyclic group having one nitrogen(N) as a ring forming atom. Accordingly, the organometallic compoundrepresented by Formula 1 may have a wide singlet energy level range anda wide triplet energy level range (for example, about 1.5 to about 3.5electron volt (eV)).

Also, since substituents of two neighboring ligands represented byFormulae 1 and 2 are not linked to each other, the organometalliccompound represented by Formulae 1 or 2 may have excellent chemical andthermal stability.

The organometallic compound represented by Formula 3 may provideexcellent charge mobility, and accordingly, an organic light-emittingdevice including the organometallic compound may have high electriccharacteristics.

An organometallic compound represented by Formula 3, in which X₂₄ isN(R₂₆) and at least one selected from X₂₁ to X₂₃ is N, may have a widesinglet energy level range and a wide triplet energy level range (forexample, about 1.5 to about 3.5 eV).

Synthesis methods of the organometallic compound represented by Formula1 may be understood to one of ordinary skill in the art by referring toSynthesis Examples provided below.

The organometallic compound represented by Formulae 1, 2, or 3 issuitable for use in an organic layer of an organic light-emittingdevice, for example, for use as a host in an emission layer of theorganic layer. Thus, another aspect provides an organic light-emittingdevice that includes:

a first electrode;

a second electrode; and

an organic layer that is disposed between the first electrode and thesecond electrode,

wherein the organic layer includes an emission layer and at least one ofthe organometallic compound represented by Formulae 1, 2, or 3.

The organic light-emitting device may have, due to the inclusion of anorganic layer including the organometallic compound represented byFormulae 1, 2, or 3, a low driving voltage, high efficiency, highbrightness, and long lifespan.

The organometallic compound represented by Formulae 1, 2, or 3 may beused between a pair of electrodes of an organic light-emitting device.For example, the organometallic compound may be included in at least oneselected from

i) a hole transport region (including, for example, at least one of ahole injection layer, a hole transport layer, a buffer layer, and anelectron blocking layer) that is disposed between the first electrodeand the emission layer, and

ii) an electron transport region (including, for example, at least oneselected from a hole blocking layer, an electron transport layer, and anelectron injection layer) that is disposed between the emission layerand the second electrode. For example, the organometallic compoundrepresented by Formulae 1, 2, or 3 may be included in the emissionlayer. In some embodiments, the organometallic compound may furtherinclude a dopant, and the organometallic compound included in theemission layer may act as a host. The emission layer may be a greenemission layer emitting green light or a blue emission layer emittingblue light, and the dopant may be a phosphorescent dopant.

The expression “(an organic layer) includes at least one organometalliccompound” used herein may include an embodiment in which “(an organiclayer) includes an identical organometallic compound selected fromorganometallic compounds represented by Formulae 1, 2, and 3 and anembodiment in which (an organic layer) includes two or more differentorganometallic compounds selected from organometallic compounds.

For example, the organic layer may include, as the organometalliccompound, only Compound 1. In this regard, Compound 1 may exist in anemission layer of the organic light-emitting device. In someembodiments, the organic layer may include, as the organometalliccompound, Compound 1 and Compound 2. In this regard, Compound 1 andCompound 2 may exist in either an identical layer (for example, Compound1 and Compound 2 all may exist in an emission layer), or differentlayers.

The first electrode may be an anode, which is a hole injectionelectrode, and the second electrode may be a cathode, which is anelectron injection electrode; or the first electrode may be a cathode,which is an electron injection electrode, or the second electrode may bean anode, which is a hole injection electrode.

For example, the first electrode is an anode, and the second electrodeis a cathode, and the organic layer includes

i) a hole transport region that is disposed between the first electrodeand the emission layer and includes at least one of a hole injectionlayer, a hole transport layer, and an electron blocking layer, and

ii) an electron transport region that is disposed between the emissionlayer and the second electrode and includes at least one selected from ahole blocking layer, an electron transport layer, and an electroninjection layer.

The term “organic layer” used herein refers to a single layer and/or aplurality of layers disposed between the first electrode and the secondelectrode of an organic light-emitting device. The “organic layer” mayinclude, in addition to an organic compound, an organometallic complexincluding metal.

FIG. 1 is a schematic view of an organic light-emitting device 10according to an embodiment. Hereinafter, the structure of an organiclight-emitting device according to an embodiment and a method ofmanufacturing an organic light-emitting device according to anembodiment will be described in connection with FIG. 1. The organiclight-emitting device 10 includes a first electrode 11, an organic layer15, and a second electrode 19, which are sequentially stacked.

In FIG. 1, a substrate may be additionally disposed under the firstelectrode 11 or above the second electrode 19. For use as the substrate,any substrate that is used in general organic light-emitting devices maybe used, and the substrate may be a glass substrate or transparentplastic substrate, each with excellent mechanical strength, thermalstability, transparency, surface smoothness, ease of handling, and waterrepellency.

The first electrode 11 may be formed by depositing or sputtering amaterial for forming the first electrode on the substrate. The firstelectrode 11 may be an anode. The material for the first electrode 11may be selected from materials with a high work function to facilitateeasy injection of holes. The first electrode 13 may be a reflectiveelectrode or a transmissive electrode. The material for the firstelectrode 11 may be indium tin oxide (ITO), indium zinc oxide (IZO), tinoxide (SnO₂), or zinc oxide (ZnO). According to another embodiment, thematerial for the first electrode 11 may be metal, such as magnesium(Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca),magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).

The first electrode 11 may have a single-layer structure or amulti-layer structure including two or more layers. For example, thefirst electrode 11 may have a three-layered structure of ITO/Ag/ITO, butthe structure of the first electrode 110 is not limited thereto.

An organic layer 15 is disposed on the first electrode 11.

The organic layer 15 may include a hole transport region, an emissionlayer, and an electron transport region.

The hole transport region may be disposed between the first electrode 11and the emission layer.

The hole transport region may include at least one of a hole injectionlayer, a hole transport layer, an electron blocking layer, and a bufferlayer.

The hole transport region may include only either a hole injection layeror a hole transport layer. According to another embodiment, the holetransport region may have a structure of hole injection layer/holetransport layer or hole injection layer/hole transport layer/electronblocking layer, which are sequentially stacked in this stated order fromthe first electrode 11.

When the hole transport region includes a hole injection layer (HIL),the hole injection layer may be formed on the first electrode 11 byusing any one of various methods, for example, vacuum deposition, spincoating, casting, or Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum deposition, thedeposition conditions may vary according to a material that is used toform the hole injection layer, and the structure and thermalcharacteristics of the hole injection layer. For example, the depositionconditions may include a deposition temperature of about 100 to about500° C., a vacuum pressure of about 10⁻⁸ to about 10⁻³ torr, and adeposition rate of about 0.01 to about 100 angstroms per second (A/sec).However, the deposition conditions are not limited thereto.

When the hole injection layer is formed using spin coating, coatingconditions may vary according to the material used to form the holeinjection layer, and the structure and thermal properties of the holeinjection layer. For example, a coating speed may be from about 2,000revolutions per minute (rpm) to about 5,000 rpm, and a temperature atwhich a heat treatment is performed to remove a solvent after coatingmay be from about 80° C. to about 200° C. However, the coatingconditions are not limited thereto.

Conditions for a hole transport layer and an electron blocking layer maybe understood by referring to conditions for forming the hole injectionlayer.

The hole transport region may include at least one selected fromm-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, Spiro-TPD, Spiro-NPB, α-NPB,TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (Pani/CSA),(polyaniline)/poly(4-styrenesulfonate) (PANI/PSS), a compoundrepresented by Formula 201 below, and a compound represented by Formula202 below:

Ar₁₀₁ to Ar₁₀₂ in Formula 201 may be each independently selected from

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anacenaphthylene group, a fluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, and a pentacenylene group; and

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anacenaphthylene group, a fluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, and a pentacenylene group, each substituted with at least one ofa deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group.

xa and xb in Formula 201 may be each independently an integer of 0 to 5,or 0, 1 or 2. For example, xa may be 1 and xb may be 0, but xa and xbare not limited thereto.

R₁₀₁ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₂₁ to R₁₂₄ in Formulae 201 and 202 maybe each independently selected from

a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₁₀ alkyl group (for example, a methyl group, an ethylgroup, a propyl group, a butyl group, a pentyl group, a hexyl group, andso on), and a C₁-C₁₀ alkoxy group (for example, a methoxy group, anethoxy group, a propoxy group, a butoxy group, a pentoxy group, and soon);

a C₁-C₁ alkyl group and a C₁-C₁₀ alkoxy group, each substituted with atleast one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, and a phosphoric acid or a saltthereof;

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenylgroup, and a pyrenyl group; and

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenylgroup, and a pyrenyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₁₀ alkyl group, and a C₁-C₁₀ alkoxy group, but they are notlimited thereto.

R₁₀₉ in Formula 201 may be selected from

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinylgroup; and

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinylgroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an aminogroup, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkylgroup, and a C₁-C₂₀ alkoxy group.

According to an embodiment, the compound represented by Formula 201 maybe represented by Formula 201A below, but is not limited thereto:

R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ in Formula 201A may be understood byreferring to the description provided herein.

For example, the compound represented by Formula 201, and the compoundrepresented by Formula 202 may include compounds HT1 to HT20 illustratedbelow, but are not limited thereto.

A thickness of the hole transport region may be in a range of about 100Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When thehole transport region includes both a hole injection layer and a holetransport layer, a thickness of the hole injection layer may be in arange of about 100 Å to about 10,000 Å, for example, about 100 Å toabout 1,000 Å, and a thickness of the hole transport layer may be in arange of about 50 Å to about 2,000 Å, for example about 100 Å to about1,500 Å. When the thicknesses of the hole transport region, the holeinjection layer, and the hole transport layer are within these ranges,satisfactory hole transporting characteristics may be obtained without asubstantial increase in driving voltage.

The hole transport region may further include, in addition to thesematerials, a charge-generation material for the improvement ofconductive properties. The charge-generation material may behomogeneously or non-homogeneously dispersed in the hole transportregion.

The charge-generation material may be, for example, a p-dopant. Thep-dopant may be one of a quinone derivative, a metal oxide, and a cyanogroup-containing compound, but is not limited thereto. Non-limitingexamples of the p-dopant are a quinone derivative, such astetracyanoquinonedimethane (TCNQ) or2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ); ametal oxide, such as a tungsten oxide or a molybdenium oxide; and acyano group-containing compound, such as Compound HT-D1 below, but arenot limited thereto.

The hole transport region may include a buffer layer.

Also, the buffer layer may compensate for an optical resonance distanceaccording to a wavelength of light emitted from the emission layer, andthus, efficiency of a formed organic light-emitting device may beimproved.

Then, an emission layer (EML) may be formed on the hole transport regionby vacuum deposition, spin coating, casting, LB deposition, or the like.When the emission layer is formed by vacuum deposition or spin coating,the deposition or coating conditions may be similar to those applied toform the hole injection layer although the deposition or coatingconditions may vary according to the material that is used to form theemission layer.

The emission layer may include a host and a dopant. The host may includeat least one selected from organometallic compounds represented byFormulae 1 to 3.

When the organic light-emitting device is a full color organiclight-emitting device, the emission layer may be patterned into a redemission layer, a green emission layer, and a blue emission layer.According to another embodiment, due to a stack structure including ared emission layer, a green emission layer, and/or a blue emissionlayer, the emission layer may emit white light. A host in the redemission layer, the green emission layer, and the blue emission layermay include the organometallic compound represented by one of Formulae 1to 3. According to an embodiment, the host in the green emission layermay include the organometallic compound represented by one of Formulae 1to 3.

A dopant in the emission layer may be a fluorescent dopant that emitslight according to a fluorescent emission mechanism or a phosphorescentdopant that emits light according to a phosphorescent emissionmechanism.

According to an embodiment, the emission layer may include a hostincluding the organometallic compound represented by one of Formulae 1to 3 and a phosphorescent dopant. The phosphorescent dopant may includean organometallic complex including a transition metal (for example,iridium (Ir), platinum (Pt), osmium (Os), or rhodium (Rh)).

The phosphorescent dopant may include at least one selected fromCompounds PD1 to PD74 below, but is not limited thereto (Compound PD1below is Ir(ppy)₃):

According to another embodiment, the phosphorescent dopant may includePtOEP or Compound PhGD illustrated below:

When the emission layer includes a host and a dopant, an amount of thedopant may be in a range of about 0.01 to about 15 parts by weight basedon 100 parts by weight of the host, but is not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å, for example, about 200 Å to about 600 Å. When thethickness of the emission layer is within this range, excellentlight-emission characteristics may be obtained without a substantialincrease in driving voltage.

Then, an electron transport region may be disposed on the emissionlayer.

The electron transport region may include at least one selected from ahole blocking layer, an electron transport layer, and an electroninjection layer.

For example, the electron transport region may have a structure of holeblocking layer/electron transport layer/electron injection layer orelectron transport layer/electron injection layer, but the structure ofthe electron transport region is not limited thereto. The electrontransport layer may have a single-layered structure or a multi-layerstructure including two or more different materials.

Conditions for forming the hole blocking layer, the electron transportlayer, and the electron injection layer which constitute the electrontransport region may be understood by referring to the conditions forforming the hole injection layer.

When the electron transport layer includes a hole blocking layer, thehole blocking layer may include, for example, at least one of BCP andBphen, but is not limited thereto.

A thickness of the hole blocking layer may be in a range of about 20 Åto about 1,000 Å, for example, about 30 Å to about 300 Å. When thethickness of the hole blocking layer is within these ranges, the holeblocking layer may have excellent hole blocking characteristics withouta substantial increase in driving voltage.

The electron transport layer may further include, in addition to theorganometallic compound represented by Formula 1, at least one selectedfrom BCP, Bphen, Alq₃, Balq, TAZ, and NTAZ.

According to another embodiment, the electron transport layer mayinclude at least one of ET1 and ET2, but are not limited thereto:

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Whenthe thickness of the electron transport layer is within the rangedescribed above, the electron transport layer may have satisfactoryelectron transport characteristics without a substantial increase indriving voltage.

Also, the electron transport layer may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include a Li complex. The Li complexmay include, for example, Compound ET-D1 (lithium quinolate, LiQ) orET-D2.

The electron transport region may include an electron injection layer(EIL) that allows electrons to be easily provided from a secondelectrode 19.

The electron injection layer may include at least one selected from,LiF, NaCl, CsF, Li₂O, BaO, and LiQ.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. When thethickness of the electron injection layer is within the range describedabove, the electron injection layer may have satisfactory electroninjection characteristics without a substantial increase in drivingvoltage.

The second electrode 19 is disposed on the organic layer 15. The secondelectrode 19 may be a cathode. A material for forming the secondelectrode 19 may be metal, an alloy, an electrically conductivecompound, and a combination thereof, which have a relatively low workfunction. For example, lithium (Li), magnesium (Mg), aluminum (Al),aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), ormagnesium-silver (Mg—Ag) may be formed as the material for forming thesecond electrode 19. To manufacture a top emission type light-emittingdevice, a transmissive electrode formed using ITO or IZO may be used asthe second electrode 19.

Hereinbefore, the organic light-emitting device has been described withreference to FIG. 1, but is not limited thereto.

A C₁-C₆₀ alkyl group used herein refers to a linear or branchedaliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms.Detailed examples thereof are a methyl group, an ethyl group, a propylgroup, an isobutyl group, a sec-butyl group, a tert-butyl group, apentyl group, an iso-amyl group, and a hexyl group. A C₁-C₆₀ alkylenegroup used herein refers to a divalent group having the same structureas the C₁-C₆₀ alkyl group.

A C₁-C₆₀ alkoxy group used herein refers to a monovalent grouprepresented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group). Detailedexamples thereof are a methoxy group, an ethoxy group, and anisopropyloxy group.

A C₂-C₆₀ alkenyl group used herein refers to a hydrocarbon group formedby substituting at least one carbon double bond in the middle or at theterminal of the C₂-C₆₀ alkyl group. Detailed examples thereof are anethenyl group, a propenyl group, and a butenyl group. A C₂-C₆₀alkenylene group used herein refers to a divalent group having the samestructure as the C₂-C₆₀ alkenyl group.

A C₂-C₆₀ alkynyl group used herein refers to a hydrocarbon group formedby substituting at least one carbon triple bond in the middle or at theterminal of the C₂-C₆₀ alkyl group. Detailed examples thereof are anethynyl group and a propynyl group. A C₂-C₆₀ alkynylene group usedherein refers to a divalent group having the same structure as theC₂-C₆₀ alkynyl group.

A C₃-C₁₀ cycloalkyl group used herein refers to a monovalent hydrocarbonmonocyclic group having 3 to 10 carbon atoms. Detailed examples thereofare a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, acyclohexyl group, and a cycloheptyl group. A C₃-C₁₀ cycloalkylene groupused herein refers to a divalent group having the same structure as theC₃-C₁₀ cycloalkyl group.

A C₂-C₁₀ heterocycloalkyl group used herein refers to a monovalentmonocyclic group having at least one hetero atom selected from N, O, P,and S as a ring-forming atom and 2 to 10 carbon atoms. Detailed examplesthereof are a tetrahydrofuranyl group, and a tetrahydrothiophenyl group.A C₂-C₁₀ heterocycloalkylene group used herein refers to a divalentgroup having the same structure as the C₂-C₁₀ heterocycloalkyl group.

A C₃-C₁₀ cycloalkenyl group used herein refers to a monovalentmonocyclic group that has 3 to 10 carbon atoms and at least one doublebond in the ring thereof and does not have aromaticity. Detailedexamples thereof are a cyclopentenyl group, a cyclohexenyl group, and acycloheptenyl group. A C₃-C₁₀ cycloalkenylene group used herein refersto a divalent group having the same structure as the C₃-C₁₀ cycloalkenylgroup.

A C₂-C₁₀ heterocycloalkenyl group used herein refers to a monovalentmonocyclic group that has at least one hetero atom selected from N, O,P, and S as a ring-forming atom, 2 to 10 carbon atoms, and at least onedouble bond in its ring. Detailed examples of the C₂-C₁₀heterocycloalkenyl group are a 2,3-dihydrofuranyl group and a2,3-dihydrothiophenyl group. A C₂-C₁₀ heterocycloalkenylene group usedherein refers to a divalent group having the same structure as theC₂-C₁₀ heterocycloalkenyl group.

A C₆-C₆₀ aryl group used herein refers to a monovalent group having acarbocyclic aromatic system having 6 to 60 carbon atoms, and a C₆-C₆₀arylene group used herein refers to a divalent group having acarbocyclic aromatic system having 6 to 60 carbon atoms. Detailedexamples of the C₆-C₆₀ aryl group are a phenyl group, a naphthyl group,an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and achrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene groupeach include two or more rings, the rings may be fused to each other.

A C₂-C₆₀ heteroaryl group used herein refers to a monovalent grouphaving a carbocyclic aromatic system that has at least one hetero atomselected from N, O, P, and S as a ring-forming atom, and 2 to 60 carbonatoms. A C₂-C₆₀ heteroarylene group used herein refers to a divalentgroup having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, P, and S as a ring-forming atom, and 2 to 60carbon atoms. Examples of the C₂-C₆₀ heteroaryl group are a pyridinylgroup, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, and an isoquinolinyl group. Whenthe C₂-C₆₀ heteroaryl group and the C₂-C₆₀ heteroarylene group eachinclude two or more rings, the rings may be fused to each other.

A C₆-C₆₀ aryloxy group used herein indicates 0A₁₀₂ (wherein A₁₀₂ is theC₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group indicates SA₁₀₃ (whereinA₁₀₃ is the C₆-C₆₀ aryl group).

A monovalent non-aromatic condensed polycyclic group used herein refersto a monovalent group that has two or more rings condensed to eachother, only carbon atoms (for example, the number of carbon atoms may bein a range of 8 to 60) as a ring forming atom (for example, having 8 to60 carbon atoms), wherein the molecular structure as a whole isnon-aromatic. An example of the monovalent non-aromatic condensedpolycyclic group is a fluorenyl group. A divalent non-aromatic condensedpolycyclic group used herein refers to a divalent group having the samestructure as the monovalent non-aromatic condensed polycyclic group.

A monovalent non-aromatic condensed heteropolycyclic group used hereinrefers to a monovalent group that has two or more rings condensed toeach other, has a heteroatom selected from N, O P, and S, other thancarbon atoms (for example, the number of carbon atoms may be in a rangeof 2 to 60), as a ring forming atom (for example, having 2 to 60 carbonatoms), wherein the molecular structure as a whole is non-aromatic. Anexample of the monovalent non-aromatic condensed heteropolycyclic groupis a carbazolyl group. A divalent non-aromatic condensedheteropolycyclic group used herein refers to a divalent group having thesame structure as the monovalent non-aromatic condensed heteropolycyclicgroup.

In the present specification, at least one substituent of thesubstituted C₁-C₆₀ alkylene group, the substituted C₂-C₆₀ alkenylenegroup, the substituted C₂-C₆₀ alkynylene group, the substituted C₃-C₁₀cycloalkylene group, the substituted C₂-C₁₀ heterocycloalkylene group,the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₂-C₁₀heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, thesubstituted C₂-C₆₀ heteroarylene group, the substituted divalentnon-aromatic condensed polycyclic group, the substituted divalentnon-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀ alkenyl group, the substitutedC₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, thesubstituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₂-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group may be selectedfrom

a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid ora salt thereof, a phosphoric acid or a salt thereof, a C₃-C₁₀ cycloalkylgroup, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), and—B(Q₁₆)(Q₁₇);

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), and—B(Q₂₆)(Q₂₇); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), and —B(Q₃₆)(Q₃₇).

Q₁ to Q₇, Q₁₁ to Q₁₇, and Q₃₁ to Q₃₇ used herein may be eachindependently selected from a hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group.

For example, at least one substituent of the substituted C₁-C₆₀ alkylenegroup, the substituted C₂-C₆₀ alkenylene group, the substituted C₂-C₆₀alkynylene group, the substituted C₃-C₁₀ cycloalkylene group, thesubstituted C₂-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀cycloalkenylene group, the substituted C₂-C₁₀ heterocycloalkenylenegroup, the substituted C₆-C₆₀ arylene group, the substituted C₂-C₆₀heteroarylene group, the substituted divalent non-aromatic condensedpolycyclic group, the substituted divalent non-aromatic condensedheteropolycyclic group, the substituted C₁-C₆₀ alkyl group, thesubstituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group,the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₂-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₂-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group may be selected from

a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid ora salt thereof, a phosphoric acid or a salt thereof, a C₃-C₁₀ cycloalkylgroup, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), and—B(Q₁₆)(Q₁₇);

a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group,an azulenyl group, a heptalenyl group, an indacenyl group, anacenaphthyl group, a fluorenyl group, a spiro-fluorenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthrenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perilenylgroup, a pentaphenyl group, a hexacenyl group, a pyrrolyl group, animidazolyl group, pyrazolyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a furinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthridinyl group, a quinoxalinyl group, a quinazolinyl group, acynolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzooxazolyl group, a benzoimidazolyl group, a furanyl group, abenzofuranyl group, a thiophenyl group, a benzothiophenyl group, athiazolyl group, an isothiazolyl group, a benzothiazolyl group, anisooxazolyl group, an oxazolyl group, a triazolyl group, a tetrazolylgroup, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group,a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, an imidazopyrimidinyl group, and an imidazopyridinyl group, eachsubstituted with at least one selected from a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclooctyl group, acyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, aphenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, aphenanthrenyl group, a fluorenyl group, a carbazolyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a pyridinyl group, apyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a phthalazinyl group,a quinoxalinyl group, a cynolinyl group, and a quinazolinyl group;

a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group,an azulenyl group, a heptalenyl group, an indacenyl group, anacenaphthyl group, a fluorenyl group, a spiro-fluorenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthrenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pyrrolyl group, animidazolyl group, a pyrazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a furinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzooxazolyl group, a benzoimidazolyl group, a furanyl group, abenzofuranyl group, a thiophenyl group, a benzothiophenyl group, athiazolyl group, an isothiazolyl group, a benzothiazolyl group, anisooxazolyl group, an oxazolyl group, a triazolyl group, a tetrazolylgroup, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group,a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, an imidazopyrimidinyl group, and an imidazopyridinyl group, eachsubstituted with at least one selected from a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclooctyl group, acyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, aphenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, aphenanthrenyl group, a fluorenyl group, a carbazolyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a pyridinyl group, apyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a phthalazinyl group,a quinoxalinyl group, a cinnolinyl group, and a quinazolinyl group, eachsubstituted with at least one selected from

a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂),—Si(Q₂₃)(Q₂₄)(Q₂₅), and —B(Q₂₆)(Q₂₇); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₆), and —B(Q₃₆)(Q₃₇), wherein

wherein Q₁ to Q₇, Q₁₁ to Q₁₇, and Q₃₁ to Q₃₇ may be each independently aphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, anazulenyl group, a heptalenyl group, an indacenyl group, an acenaphthylgroup, a fluorenyl group, a spiro-fluorenyl group, a phenalenyl group, aphenanthrenyl group, an anthracenyl group, a fluoranthrenyl group, atriphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenylgroup, a picenyl group, a perylenyl group, a pentaphenyl group, ahexacenyl group, a pyrrolyl group, an imidazolyl group, a pyrazolylgroup, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, apyridazinyl group, an isoindolyl group, an indolyl group, an indazolylgroup, a furinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzooxazolyl group, abenzoimidazolyl group, a furanyl group, a benzofuranyl group, athiophenyl group, a benzothiophenyl group, a thiazolyl group, anisothiazolyl group, a benzothiazolyl group, an isooxazolyl group, anoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolylgroup, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, animidazopyrimidinyl group, and an imidazopyridinyl group, eachsubstituted with at least one selected from a hydrogen, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxygroup, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclooctyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, an anthracenylgroup, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, acarbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, apyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aphthalazinyl group, a quinoxalinyl group, a cinnolinyl group, or aquinazolinyl group, but they are not limited thereto.

The “biphenyl group” used therein refers to “a phenyl group substitutedwith a phenyl group.”

Hereinafter, a compound and an organic light-emitting device accordingto embodiments are described in detail with reference to SynthesisExamples and Examples. However, the organic light-emitting device is notlimited thereto. The wording “B was used instead of A” used indescribing the Synthesis Examples means that a molar equivalent of A wasidentical to a molar equivalent of B.

EXAMPLE Synthesis Example 1 Synthesis of Compound 1

5.16 g (30 mmol) of Ligand A and 2.04 g (10 mmol) of Al(OCH(CH₃)₂)₃ wereplaced into a pressure-resistant tube. 100 mL of ethanol was addedthereto and then a reaction was allowed to proceed at a temperature of85° C. for 18 hours, and then, when the reaction stopped, the resultantwas filtered while in a hot state, and washed with ethanol,dichloromethane (CH₂Cl₂), and hexane and then dried to obtain 2.97 g(55%) of Compound 1.

Calculated element analysis values of Compound 1 (C: 66.66, H: 3.92, N:15.52), measured element analysis values of Compound 1 (C: 67.64, H:3.975, N 15.52)

Synthesis Example 2 Synthesis of Compound 61

5.67 g (30 mmol) of Ligand B and 2.04 g (10 mmol) of Al(OCH(CH₃)₂)₃ wereplaced into a pressure-resistant tube. 50 mL of ethanol was addedthereto and then a reaction was allowed to proceed at a temperature of85° C. for 72 hours, and then, when the reaction stopped, the resultantwas filtered while in a hot state, and washed with ethanol,dichloromethane (CH₂Cl₂), and hexane and then dried to obtain 1.36 g(23%) of Compound 61.

Calculated element analysis values of Compound 61 (C: 67.01, H: 3.58, N:7.10), measured element analysis values of Compound 61 (C: 67.99, H:3.51, N 6.95)

Synthesis Example 3 Synthesis of Compound 62

5.67 g (30 mmol) of Ligand C and 2.04 g (10 mmol) of Al(OCH(CH₃)₂)₃ wereplaced into a pressure-resistant tube. 40 mL of ethanol was addedthereto and then a reaction was allowed to proceed at a temperature of85° C. for 72 hours, and then, when the reaction stopped, the resultantwas filtered while in a hot state, and washed with ethanol,dichloromethane (CH₂Cl₂), and hexane and then dried to obtain 3.13 g(53%) of Compound 62.

Calculated element analysis values of Compound 62 (C: 67.01, H: 3.58, N:7.10), measured element analysis values of Compound 62 (C: 67.56, H:2.59, N 7.00)

Synthesis Example 4 Synthesis of Compound 96

5.55 g (30 mmol) of Ligand D and 2.04 g (10 mmol) of Al(OCH(CH₃)₂)₃ wereplaced into a pressure-resistant tube. 50 mL of ethanol was addedthereto and then a reaction was allowed to proceed at a temperature of85° C. for 72 hours, and then, when the reaction stopped, the resultantwas filtered while in a hot state, and washed with ethanol,dichloromethane (CH₂Cl₂), and hexane and then dried to obtain 3.04 g(52.5%) of Compound 96.

Calculated element analysis values of Compound 96 (C: 68.40, H: 3.13, N:7.25), measured element analysis values of Compound 96 (C: 69.33, H:2.899, N 7.05)

Comparative Example 1 Synthesis of Compound A

5.14 g (30 mmol) of Ligand E and 2.04 g (10 mmol) of Al(OCH(CH₃)₂)₃ wereplaced into a pressure-resistant tube. 50 mL of ethanol was addedthereto and then a reaction was allowed to proceed at a temperature of85° C. for 20 hours, and then, when the reaction stopped, the resultantwas filtered while in a hot state, and washed with ethanol,dichloromethane (CH₂Cl₂), and hexane and then dried to obtain 3.60 g(67%) of Compound A.

Calculated element analysis values of Compound A (C: 73.73, H: 4.50, N:7.82), measured element analysis values of Compound A (C: 73.36, H:4.836, N 7.74)

Evaluation Example 1 Thermal Characteristics Evaluation

Thermal analysis was performed on Compounds 1, 61, 62, 96 and A by usingthermogravimetric analysis (TGA) and differential scanning calorimetry(DSC) (N₂ atmosphere, temperature range: from room temperature to 800°C. (10° C./min)-TGA, from room temperature to 450□-DSC, Pan Type: Pt Panin disposable Al Pan(TGA), and disposable Al pan(DSC)), and resultsthereof are shown in Table 1.

TABLE 1 Compound No. Td5 Tg Tm Ts Compound 1 314 167.27 n/a n/a Compound61 284 n/a n/a n/a Compound 62 305 n/a n/a n/a Compound 96 330 n/a n/an/a Compound A 272 94.29 n/a n/a

From Table 1, it was confirmed that Compounds 1, 61, 62 and 96 hadexcellent thermal stability.

Example 1

An ITO glass substrate was cut to a size of 50 mm×50 mm×0.5 mm and then,sonicated in acetone isopropyl alcohol and pure water, each for 15minutes, and then, washed by exposure to UV ozone for 30 minutes.

Then, m-MTDATA was deposited on an ITO electrode (anode) of the glasssubstrate at a deposition speed of 1 Å/sec to form a hole injectionlayer having a thickness of 600 Å, and then, α-NPD was deposited on thehole injection layer at a deposition speed of 1 Å/sec to form a holetransport layer having a thickness of 250 Å. Ir(ppy)₃ (dopant) andCompound 1 (host) were co-deposited on the hole transport layer at adeposition speed of 0.1 Å/sec and a deposition speed of 1 Å/sec,respectively, to form an emission layer having a thickness of 400 Å.

BAlq was deposited on the emission layer at a deposition speed of 1Å/sec to form a hole blocking layer having a thickness of 50 Å, and Alq₃was deposited on the hole blocking layer to form an electron transportlayer having a thickness of 300 A, and then, LiF was deposited on theelectron transport layer to form an electron injection layer having athickness of 10 Å, and then, Al was vacuum deposited on the electroninjection layer to form a second electrode (cathode) having a thicknessof 1200 Å, thereby completing manufacturing of an organic light-emittingdevice having a structure of ITO/m-MTDATA (600 Å)/α-NPD (250 Å)/Compound1+10% (Ir(ppy)₃) (400 Å)/BAlq(50 Å)/Alq₃(300 Å)/LiF(10 Å)/Al(1,200 Å).

Example 2

An organic light-emitting device having the structure of ITO/m-MTDATA(600 Å)/α-NPD (250 Å)/Compound 61+10% (Ir(ppy)₃) (400 Å)/BAlq(50Å)/Alq₃(300 Å)/LiF(10 Å)/Al(1,200 Å) was manufactured in the same manneras in Example 1, except that in forming an emission layer, Compound 61was used instead of Compound 1.

Example 3

An organic light-emitting device having the structure of ITO/m-MTDATA(600 Å)/α-NPD (250 Å)/Compound 62+10% (Ir(ppy)₃) (400 Å)/BAlq(50Å)/Alq₃(300 Å)/LiF(10 Å)/Al(1,200 Å) was manufactured in the same manneras in Example 1, except that in forming an emission layer, Compound 62was used instead of

Compound 1.

Example 4

An organic light-emitting device having the structure of ITO/m-MTDATA(600 Å)/α-NPD (250 Å)/Compound 96+10% (Ir(piq)₃) (400 Å)/BAlq(50Å)/Alq₃(300 Å)/LiF(10 Å)/Al(1,200 Å) was manufactured in the same manneras in Example 1, except that in forming an emission layer, as a host,Compound 96 was used instead of Compound 1, and as a dopant, Ir(piq)₃(Ir(piq)₃ is identical to the Compound PD14) was used instead ofIr(ppy)₃.

Comparative Example 1

An organic light-emitting device having the structure of ITO/m-MTDATA(600 Å)/α-NPD (250 Å)/Compound A+10% (Ir(ppy)₃) (400 Å)/BAlq(50Å)/Alq3(300 Å)/LiF(10 Å)/Al(1,200 Å) was manufactured in the same manneras in Example 1, except that in forming an emission layer, Compound Awas used instead of Compound 1.

Comparative Example 2

An organic light-emitting device having the structure of ITO/m-MTDATA(600 Å)/α-NPD (250 Å)/CBP+10% (Ir(ppy)₃) (400 Å)/BAlq(50 Å)/Alq3(300Å)/LiF(10 Å)/Al(1,200 Å) was manufactured in the same manner as inExample 1, except that in forming an emission layer, CBP was usedinstead of Compound 1.

Comparative Example 3

An organic light-emitting device having the structure of ITO/m-MTDATA(600 Å)/α-NPD (250 Å)/CBP+10% (Ir(piq)₃) (400 Å)/BAlq(50 Å)/Alq3(300Å)/LiF(10 Å)/Al(1,200 Å) was manufactured in the same manner as inExample 3, except that in forming an emission layer, as a dopant,Ir(piq)₃ was used instead of Ir(ppy)₃.

Evaluation Example 2 Evaluation of Characteristics of an OrganicLight-Emitting Device

Characteristics of the organic light-emitting devices manufacturedaccording to Examples 1 to 4 and Comparative Examples 1 to 3 wereevaluated according to the following methods, and results thereof areshown in Table 2.

(1) Change in Current Density According to Voltage

Regarding the manufactured organic light-emitting devices, a currentflowing in a unit device was measured by using a current-voltage meterwhile a voltage was raised from −5 V to 10 V, and the measured currentvalue was divided by an area.

(2) Change in Brightness According to Voltage

Regarding the manufactured organic light-emitting devices, brightnesswas measured by using Minolta Cs-1000A while a voltage was raised from−5 V to 10 V.

(3) Luminescence Efficiency

Current efficiency (candelas per ampere, cd/A) was measured at the samecurrent density (10 milliamperes per square centimeter, mA/cm²) by usingbrightness, current density, and voltage measured according to (1) and(2).

TABLE 2 Driving Current Power Voltage Efficiency Efficiency Host Dopant(V) (cd/A) (Lm/W) Example 1 Compound 1 Ir(ppy)₃ 5.9 29.0 15.4 Example 2Compound 61 Ir(ppy)₃ 6.0 27.5 14.4 Example 3 Compound 62 Ir(ppy)₃ 5.830.5 16.5 Example 4 Compound 96 Ir(piq)₃ 5.8 7.8 4.2 ComparativeCompound A Ir(ppy)₃ 7.0 25.5 11.4 Example 1 Comparative CBP Ir(ppy)₃ 6.630.5 14.5 Example 2 Comparative CBP Ir(piq)₃ 6.2 7.4 3.7 Example 3

From Table 2, it was confirmed that the organic light-emitting devicesof Examples 1 to 3 had lower driving voltages and higher currentefficiency and power efficiency than the organic light-emitting devicesof Comparative Examples 1 and 2, and the organic light-emitting deviceof Example 4 had a lower driving voltage than the organic light-emittingdevice of Comparative Example 3.

The organometallic compound according to embodiments has excellentelectric characteristics and thermal stability. Accordingly, an organiclight-emitting device including the organometallic compound may have alow driving voltage, high efficiency, high brightness, and a longlifespan.

It should be understood that the exemplary embodiments described hereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the present disclosure as definedby the following claims.

What is claimed is:
 1. An organometallic compound represented byFormulae 1, 2, or 3:

wherein in Formulae 1, 2, and 3, M is Al, Ga, Be, Mg, or Zn; CY₁, CY₂,CY₁₁, and CY₂₁ are each independently a nitrogen-containing heterocyclicgroup; CY₁₂ is selected from an aromatic cyclic group and a non-aromaticcyclic group; X₁ is N or C, X₁₁ is N or C, X₁₂ is N or C, X₂₁ is N orCR₂₁, X₂₂ is N or CR₂₂, X₂₃ is N or CR₂₃, and X₂₄ is S, O, Si(R₂₄)(R₂₅),or N(R₂₆); Z₁, Z₂, Z₁₁, Z₁₂, Z₂₁, and R₂₁ to R₂₆ are each independentlya hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid or a salt thereof, asulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, asubstituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₂-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), or —B(Q₆)(Q₇); Z₃and Z₁₃ are each independently the same or different electronwithdrawing group; a1, a2, a3, a11, a12, and a21 are each independentlyan integer selected from 0 to 5; a13 is an integer selected from 1 to 5;n1 is an integer selected from 1 to 3; L₁ is selected from a monovalentorganic ligand, a divalent organic ligand, and a trivalent organicligand; n2 is an integer selected from 0 to 3; provided that CY₂ inFormula 1 is not a triazine, a pyridazine, or a pyrimidine; substituentsof two adjacent ligands in Formulae 1 and 2 are not linked to eachother; in Formula 3, when X₂₄ is N(R₂₆), at least one selected from X₂₁to X₂₃ is N; at least one substituent of the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₂-C₆₀ heteroaryl group, the substituted a monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group is selected from adeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted withat least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), and —B(Q₁₆)(Q₁₇); a C₃-C₁₀ cycloalkylgroup, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group; a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid or a salt thereof, asulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₂-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), and—B(Q₂₆)(Q₂₇); and —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), or —B(Q₃₆)(Q₃₇);wherein Q₁ to Q₇, Q₁₁ to Q₁₇, Q₂₁ to Q₂₇, and Q₃₁ to Q₃₇ are eachindependently selected from a hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₂-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group.
 2. Theorganometallic compound of claim 1, wherein CY₂ is a nitrogen-containingheterocyclic group comprising one nitrogen as a ring forming element. 3.The organometallic compound of claim 1, wherein CY₁, CY₁₁, and CY₂₁ areeach independently selected from a pyridine, a pyrazine, a pyrimidine, apyridazine, a triazine, a quinoline, an isoquinoline, a benzoquinoline,a quinoxaline, a quinazoline, a triazole, an oxazole, a benzooxazole,and a benzoisoquinoline, and CY₂ is selected from a pyridine, aquinoline, and an isoquinoline.
 4. The organometallic compound of claim1, wherein CY₁₂ is selected from a benzene, a naphthalene, a fluorene, aphenanthrene, an anthracene, a fluoranthene, a triphenylene, a pyrene,and a chrysene.
 5. The organometallic compound of claim 1, wherein Z₁,Z₂, Z₁₁, Z₁₂, Z₂₁, and R₂₁ to R₂₆ are each independently selected from ahydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid or a salt thereof, asulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, aC₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group anda C₁-C₂₀ alkoxy group, each substituted with at least one selected froma deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid or a salt thereof, a sulfonic acid or a saltthereof, and a phosphoric acid or a salt thereof; a phenyl group, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isooxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a furinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzooxazolyl group, an isobenzooxazolylgroup, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, atriazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group,an imidazopyridinyl group, and an imidazopyrimidinyl group; a phenylgroup, a pentalenyl group, an indenyl group, a naphthyl group, anazulenyl group, a heptalenyl group, an indacenyl group, an acenaphthylgroup, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenylgroup, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenylgroup, an anthracenyl group, a fluoranthenyl group, a triphenylenylgroup, a pyrenyl group, a chrysenyl group, a naphthacenyl group, apicenyl group, a perylenyl group, a pentaphenyl group, a hexacenylgroup, a pentacenyl group, a rubicenyl group, a coronenyl group, anovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group,an imidazolyl group, a pyrazolyl group, a thiazolyl group, anisothiazolyl group, an oxazolyl group, an isooxazolyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, anisoindolyl group, an indolyl group, an indazolyl group, a furinyl group,a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aphthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthridinyl, an acridinyl, a phenanthrolinyl, a phenazinyl, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzooxazolyl group, an isobenzooxazolylgroup, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, atriazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinylgroup, and an imidazopyrimidinyl group, each substituted with at leastone selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isooxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a furinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl, an acridinyl, aphenanthrolinyl, a phenazinyl, a benzoimidazolyl group, a benzofuranylgroup, a benzothiophenyl group, an isobenzothiazolyl group, abenzooxazolyl group, an isobenzooxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, an imidazopyridinyl group, animidazopyrimidinyl group, and a biphenyl group; and —N(Q₁)(Q₂) and—Si(Q₃)(Q₄)(Q₅), wherein Q₁ to Q₅ are each independently selected from ahydrogen, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, anaphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenylgroup, a fluorenyl group, a chrysenyl group, a carbazolyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a pyridinyl group, a pyrimidinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, aquinazolinyl group, and a quinoxalinyl group.
 6. The organometalliccompound of claim 1, wherein Z₁, Z₂, Z₁₁, Z₁₂, Z₂₁, and R₂₁ to R₂₆ areeach independently selected from a hydrogen, a deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidor a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acidor a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; aC₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, and a phosphoric acid or a saltthereof; a phenyl group, a naphthyl group, a fluorenyl group, aspiro-fluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinylgroup, a pyrimidinyl group, a quinolinyl group, an isoquinolinyl group,a quinoxalinyl group, a quinazolinyl group, and a carbazolyl group; anda phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrimidinylgroup, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group,a quinazolinyl group, and a carbazolyl group, each substituted with atleast one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group,a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid or a salt thereof,a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof,a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthylgroup, a fluorenyl group, a spiro-fluorenyl group, a phenalenyl group, aphenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenylgroup, a pyridinyl group, a pyrimidinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, and acarbazolyl group.
 7. The organometallic compound of claim 1, wherein Z₃and Z₁₃ are selected from —F, a cyano group, a nitro group, a pyridinylgroup, and a pyrimidinyl group; and a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, a pyridinyl group, and apyrimidinyl group, each substituted with at least one selected from —F,a cyano group, a nitro group, a pyridinyl group, and a pyrimidinylgroup.
 8. The organometallic compound of claim 1, wherein a3 in Formula1 is an integer selected from 1 to
 5. 9. The organometallic compound ofclaim 1, wherein at least one group Z₁ is an electron withdrawing group,and at least one group Z₁₁ is an electron withdrawing group.
 10. Theorganometallic compound of claim 1, wherein the organometallic compoundis represented by one of Formulae 1A to 1K:

wherein in Formulae 1A and 1K, M, Z₁ to Z₃, a1 to a3, n1, L₁, and n2 arethe same as defined in claim 1, and CY₂ is a pyridine, a quinoline, oran isoquinoline.
 11. The organometallic compound of claim 10, wherein Z₁to Z₃ are each independently selected from a hydrogen, —F, a cyanogroup, a nitro group, a methyl group, an ethyl group, a propyl group, ann-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group,an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentylgroup, an n-hexyl group, an isohexyl group, a sec-hexyl group, atert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptylgroup, a tert-heptyl group, an n-octyl group, an isooctyl group, asec-octyl group, a tert-octyl group, an n-nonyl group, an isononylgroup, a sec-nonyl group, a tert-nonyl group, an n-decanyl group, anisodecanyl group, a sec-decanyl group, a tert-decanyl group, a methoxygroup, an ethoxy group, a propoxy group, a butoxy group, a pentoxygroup, a phenyl group, a naphthyl group, a pyridinyl group, and apyrimidinyl group; and a methyl group, an ethyl group, a propyl group,an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butylgroup, an n-pentyl group, an isopentyl group, a sec-pentyl group, atert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexylgroup, a tert-hexyl group, an n-heptyl group, an isoheptyl group, asec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctylgroup, a sec-octyl group, a tert-octyl group, an n-nonyl group, anisononyl group, a sec-nonyl group, a tert-nonyl group, an n-decanylgroup, an isodecanyl group, a sec-decanyl group, a tert-decanyl group, amethoxy group, an ethoxy group, a propoxy, a butoxy group, a pentoxygroup, a phenyl group, a naphthyl group, a pyridinyl group, and apyrimidinyl group, each substituted with at least one selected from —F,a cyano group, a nitro group, a C₁-C₂₀ alkoxy group, a C₁-C₂₀ alkoxygroup, a phenyl group, a naphthyl group, a pyridinyl group, and apyrimidinyl group.
 12. The organometallic compound of claim 1, whereinthe organometallic compound is represented by Formulae 2A, 2B, or 2C:

wherein in Formulae 2A to 2C, M, Z₁₂, Z₁₃, a12, n1, L₁, and n2 are thesame as defined in claim 1; Z_(13a) and Z_(13b) are the same ordifferent, and have the same definition as Z₁₃ in claim 1; X₁₃ is N orCR₁₃, X₁₄ is N or CR₁₄, X₁₅ is N or CR₁₅, and X₁₆ is N or CR₁₆; R₁₃ toR₁₆ are the same or different and each has the same definition as Z₁₁ inclaim
 1. 13. The organometallic compound of claim 12, wherein Z₁₂ andR₁₃ to R₁₆ are each independently selected from a hydrogen, —F, a cyanogroup, a nitro group, a methyl group, an ethyl group, a propyl group, ann-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group,an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentylgroup, an n-hexyl group, an isohexyl group, a sec-hexyl group, atert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptylgroup, a tert-heptyl group, an n-octyl group, an isooctyl group, asec-octyl group, a tert-octyl group, an n-nonyl group, an isononylgroup, a sec-nonyl group, a tert-nonyl group, an n-decanyl group, anisodecanyl group, a sec-decanyl group, a tert-decanyl group, a methoxygroup, an ethoxy group, a propoxy group, a butoxy group, a pentoxygroup, a phenyl group, a naphthyl group, a pyridinyl group, and apyrimidinyl group; and a methyl group, an ethyl group, a propyl group,an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butylgroup, an n-pentyl group, an isopentyl group, a sec-pentyl group, atert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexylgroup, a tert-hexyl group, an n-heptyl group, an isoheptyl group, asec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctylgroup, a sec-octyl group, a tert-octyl group, an n-nonyl group, anisononyl group, a sec-nonyl group, a tert-nonyl group, an n-decanylgroup, an isodecanyl group, a sec-decanyl group, a tert-decanyl group, amethoxy group, an ethoxy group, a propoxy, a butoxy group, a pentoxygroup, a phenyl group, a naphthyl group, a pyridinyl group, and apyrimidinyl group, each substituted with at least one selected from —F,a cyano group, a nitro group, a C₁-C₂₀ alkoxy group, a C₁-C₂₀ alkoxygroup, a phenyl group, a naphthyl group, a pyridinyl group, and apyrimidinyl group; and Z₁₃, Z_(13a), and Z_(13b) are each independentlyselected from —F, a cyano group, a nitro group, a pyridinyl group, and apyrimidinyl group; and a methyl group, an ethyl group, a propyl group,an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butylgroup, an n-pentyl group, an isopentyl group, a sec-pentyl group, atert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexylgroup, a tert-hexyl group, an n-heptyl group, an isoheptyl group, asec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctylgroup, a sec-octyl group, a tert-octyl group, an n-nonyl group, anisononyl group, a sec-nonyl group, a tert-nonyl group, an n-decanylgroup, an isodecanyl group, a sec-decanyl group, a tert-decanyl group, amethoxy group, an ethoxy group, a propoxy group, a butoxy group, apentoxy group, a phenyl group, a naphthyl group, a pyridinyl group, anda pyrimidinyl group, each substituted with at least one selected from—F, a cyano group, a nitro group, a pyridinyl group, and a pyrimidinylgroup.
 14. The organometallic compound of claim 12, wherein Z₁₃,Z_(13a), and Z_(13b) are each independently selected from —F, a cyanogroup, a nitro group, a pyridinyl group, a pyrimidinyl group, —CF₃, and—CF₂CF₃.
 15. The organometallic compound of claim 1, wherein theorganometallic compound is represented by one of Formulae 3A to 3D:

wherein in Formulae 3A to 3D, M, Z₂₁, a21, X₂₁ to X₂₃, R₂₄ to R₂₆, n1,L₁, and n2 are the same as defined in claim 1, and at least one of X₂₁to X₂₃ in Formula 3D is N.
 16. The organic light-emitting device ofclaim 15, wherein Z₂₁ and R₂₁ to R₂₆ are each independently selectedfrom a hydrogen, —F, a cyano group, a nitro group, a methyl group, anethyl group, a propyl group, an n-butyl group, an isobutyl group, asec-butyl group, a tert-butyl group, an n-pentyl group, an isopentylgroup, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, anisohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptylgroup, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, ann-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group,an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonylgroup, an n-decanyl group, an isodecanyl group, a sec-decanyl group, atert-decanyl group, a methoxy group, an ethoxy group, a propoxy group, abutoxy group, a pentoxy group, a phenyl group, a naphthyl group, apyridinyl group, and a pyrimidinyl group; and a methyl group, an ethylgroup, a propyl group, an n-butyl group, an isobutyl group, a sec-butylgroup, a tert-butyl group, an n-pentyl group, an isopentyl group, asec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexylgroup, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, anisoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octylgroup, an isooctyl group, a sec-octyl group, a tert-octyl group, ann-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group,an n-decanyl group, an isodecanyl group, a sec-decanyl group, atert-decanyl group, a methoxy group, an ethoxy group, a propoxy, abutoxy group, a pentoxy group, a phenyl group, a naphthyl group, apyridinyl group, and a pyrimidinyl group, each substituted with at leastone selected from —F, a cyano group, a nitro group, a C₁-C₂₀ alkoxygroup, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, apyridinyl group, and a pyrimidinyl group.
 17. The organometalliccompound of claim 1, wherein the organometallic compound is one ofCompounds 1 to 168:


18. An organic light-emitting device comprising: a first electrode; asecond electrode; and an organic layer disposed between the firstelectrode and the second electrode, wherein the organic layer comprisesan emission layer, and at least one of the organometallic compound ofclaim
 1. 19. The organic light-emitting device of claim 18, wherein thefirst electrode is an anode, the second electrode is a cathode, and theorganic layer comprises i) a hole transport region disposed between thefirst electrode and the emission layer and comprises at least one of ahole injection layer, a hole transport layer, and an electron blockinglayer, and ii) an electron transport region disposed between theemission layer and the second electrode and comprising at least oneselected from a hole blocking layer, an electron transport layer, and anelectron injection layer.
 20. The organic light-emitting device of claim18, wherein the emission layer comprises the organometallic compound.